


Equation

by CatrinaSL



Series: Tales from the Supply Closet [1]
Category: Marvel Cinematic Universe
Genre: Background Jane/Thor, Explicit Sexual Content, F/M, Hair-pulling, Misuse of Storage Closets, Multi, Oral Sex, Past Darcy/Loki, Past Steve/Howard/Peggy, Polyamory, Polyamory Negotiations, SHIP DARCY LEWIS WITH ALL THE THINGS, Sex, Vaginal Fingering, Wall Sex
Language: English
Status: Completed
Published: 2018-01-02
Updated: 2018-01-02
Packaged: 2019-02-27 09:25:49
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,509
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13245312
Author URL: https://archiveofourown.org/users/CatrinaSL/pseuds/CatrinaSL
Summary: Bucky notices the way Darcy reacts to Loki's lurking, and he thinks she should do something about it.





	Equation

Darcy looked up from her book when she sensed Bucky tracking something—or someone—with his gaze.

She spotted his quarry: a slender dark haired man with a darker gaze, who slid past the entrance to the common room dressed in his usual dark green and gold. Sans helmet, thankfully. Because wouldn't _that_ just be the perfect first impression.

Darcy nudged Bucky with her leg after Loki drifted out of sight. He looked back to her with a smile, putting his hand on her thigh and giving it a squeeze.

"You good?" she asked.

Bucky nodded tranquilly. "I've been seeing him around more, lately. You know him." It wasn't a question.

Darcy ducked her head in a nod, getting ready for The Conversation. "My ex."

"Which one?" Bucky asked, with only a small frown.

"Thor's brother?"

"Oh, that explains the..." He waved his hand in front of his chest, searching for the right word.

"Clothes?" Darcy filled in.

"I was gonna say the bearing. Y'know, the way he holds himself. Lordly."

"Godly," she corrected.

Bucky looked skeptically amused as he nodded. "Right."

Darcy went back to her book to hide her relief; she'd been expecting a much more thorough questioning.

Loki was the only person she had dated who she hadn't split with (amicably or otherwise). They just kind of... stopped. It was hard to have a relationship with someone when they disappeared and were presumed lost to space and time for months before reappearing, burdened with the glorious purpose of conquering the earth (or at least New York). Even after Thor gave him some cognitive recalibration, things were kind of hectic (not to mention dramatic), so she and Loki had never been able to sit down and have one of those awkward "are we or aren't we" conversations.

Loki couldn't possibly have expected Darcy to wait around forever (she loved Jane, but waiting two years just because your man was like, "brb" and then _didn't_ brb? No thank you), and besides, she and Bucky liked each other. She wasn't willing to ditch him just because Loki kept showing up every few weeks to lurk in her eye line. She didn't love the idea of leaving things up in the air like that, but she also wasn't quite up for having the "Sorry I got a new boyfriend when I thought you were dead twice; maybe call me next time or at least think about texting or something" chat.

About half an hour after their trickster god sighting, Bucky said, "Why?"

Darcy blinked at him, communicating her supreme confusion.

"Why," Bucky repeated, "is he your ex?"

Darcy tried to sigh inwardly, but a little bit of it slipped out as she answered. "Well, there are a lot of reasons. For one—"

"No," he interrupted. "I don't wanna hear the sad story of how you broke his heart into pieces or vice versa. I just wanna know why he isn't your man right now."

"Isn't that the same thing?"

Bucky considered the question. "I guess it is," he said. "Lemme put it this way:" He pried her legs from around his waist and stood, lifting her to her feet and relieving her of her book. Then he slapped her ass, giving her a shove in the direction Loki had gone. "You want him. Go get him."

"But—" Darcy protested immediately. "I sort of already have a boyfriend? Unless this is your way of breaking up with me?"

Bucky laughed as he stretched himself out on the couch, getting comfortable with Darcy's book. "You twenty-first century girls are so old fashioned."

Darcy turned her head to one side, not sure her brain was interpreting sounds correctly. "I can't believe I just heard that, with my own two ears."

"What's wrong with being with more than one person at a time?" Bucky wanted to know.

"Nothing," Darcy replied. "There's just usually more communication than this. Like, I didn't even know that was an option with you."

He shrugged. "Now you do. Go get 'em, tiger."

"But... I don't know if Loki—"

"That's why you're going to find out," Bucky told her. "I'm not saying go jump him in the supply closet. Open the lines of communication. Talk to him. Then you and I can talk. Then you can talk to him again. And he and I can talk, if we need to. So on and so forth, until the end of time, amen. It ain't hard, doll."

She pushed his face back against the back of the couch in disgust. "Don't try to adorable-40s-endearment your way outta this one, Buckaroo."

He caught her wrist and kissed it. "Quit stallin', Sweetcheeks," he sassed back. "I'm not stupid; I can see how much you want each other."

"You... can?" Darcy stuttered.

"I've seen him around maybe six times before? Never anywhere you're not. And when you notice  _ him _ , you make that face."

Darcy frowned. "What face?"

Bucky sighed and sat up, reaching for her and tugging her over to stand between his legs. He pushed her hair out of her face and kissed her cheek. "That face you make when you want me to put my hand up your skirt at the movies," he whispered in her ear.

Darcy shivered.

Bucky grinned and nodded at her. "That one."

He tilted his chin up and kissed her, long and sure, without a hint of hesitation. Darcy knew then that he really meant what he said; he wasn't just putting on a brave face because he thought that was what she wanted.

"Why are you still here?" he asked when they parted breathlessly.

"You were kissing me," she griped.

Bucky laughed, and the sound was infectious; Darcy couldn't help but smile as she rolled her eyes at him.

"Fine, I'm going, happy?" she said, and headed for the door.

"Only if you are, Sweet Peach."

Darcy paused before getting on the elevator and stepped back over to the entrance to the common area. "Buck?"

"Yeah, Darce?" Bucky said, looking up from Darcy's book.

"What if he, uh... the storage closet thing?"

Bucky turned back to the book, raising one arm to give her an enthusiastic thumbs up.

"You're the best," Darcy squeaked, dashing over to kiss him on the head.

"Damn right I am," he agreed, waving her away. "Now get outta here."

* * *

 

Darcy made an inner to-do list as she strode quickly down the hallway toward Jane's lab.

1\. Find Loki (which wouldn't be too hard; he would never admit it, but when they were on Earth, he stuck to Thor like glue)

2\. Talk to Loki (more like get him to listen, but she'd been able to do that before. Once or twice).

3\. ??? (Kissing or perhaps yelling were possibilities here, depending on how high the listening to talking ratio was.)

4\. Profit (she wasn't quite sure how this one was going to work, actually, but it was a nice list-ender. She had read somewhere that successful people often had more than two things on a list when planning a new venture).

Darcy could hear Jane talking to Thor excitedly about her project, how it was going to bring humanity closer to understanding how the Bifrost actually worked.

She took a deep breath before going inside. She was going to say, "Hey, everyone. Sorry for interrupting. Mind if I borrow Loki?" It would be a miracle if they got out of there without thunder-hugs or disapproving frowns from Jane (who had never thought Loki was good enough for Darcy), but she had to risk it. There was going to be some inevitable awkwardness, and hopefully she could get it out of the way quickly and get back to being happy, whether it was with Loki or without him.

Just as she was about to turn the corner and head in, Loki appeared.

"Darcy," he said quietly, sounding as surprised as she'd ever heard him.

"Uh, hi," she replied, leaning to peek into the lab to see if Jane and Thor were paying attention. Loki stopped her.

"I will return momentarily, brother," Loki called. "I am starved. Surely there is something edible in the break room."

Thor said something, but Darcy couldn't quite make it out, and also, Loki was looking at her like he wanted to eat _her_ in the break room. Which was against the rules. It specifically said so in the Tony Stark-edited Stark Industries employee manual: "That's what the supply closets are for, people! Just keep it down out of respect those of your co-workers who don't want to hear that kind of thing, okay, Barton?"

"Can I talk to you" was on its way out of her mouth when Loki covered it with his, backing her against the wall and feeling for the doorknob of the nearby supply closet. Once inside, he paused to shed his coat/cloak/cape thing, keeping her tongue occupied with his.

"We really—should have a conversation," she panted when his lips moved to her neck and his hands to her breasts.

"What is there to discuss?" he replied, flicking her nipple with his thumb to make her gasp. "You have abandoned your paramour to come to me. Does this not merit celebration?"

"Wait," Darcy told him, pausing him in his intent to take off her shirt.

"Why?" Loki purred. "You desire me, Darcy Lewis. I can feel it." His hand brushed across the front of her yoga pants and she fought against a shudder (and lost). "I can see it." Darcy could well believe that her traitorous pupils were blown wide with desire, but Loki was likely talking about her nipples, hard against her v-neck shirt, aching for his touch. "I can smell it."

"Okay," Darcy pronounced, pushing him back a step with her hand on his chest. "That's both creepy and kind of hot, but we need a make out time-out. We really do need to talk, because the thing is, I didn't."

"Didn't what?" Loki asked, infuriatingly handsome and ridiculously desirable.

"I didn't 'leave my paramour,' or whatever you said. And his name is Bucky."

"I don't ca—"

Darcy halted his incorrect opinion before he could so condescendingly bestow it. "I know you don't care, Loki, but I do, because he's my boyfriend, and that means you should treat him with respect."

Loki's expression went from angry to confused and then back to angry.

"Yeah, I know. Here's the thing: _he_ told me to come here. He noticed that I want to jump your bones pretty much every time I see you, so he said I should come see if that's okay with you."

"How honorable of him," Loki said, smiling again (and advancing again! Abort! Abort! Misunderstanding imminent!) "To step aside—"

"Yeah, he's not stepping aside," Darcy interrupted, crossing her arms over her chest to shut her nipples up communicating things that were counterproductive to her [Darcy + Bucky] + [Darcy + Loki] = ♡♡♡ equation.

"Then you are... being untrue? With permission? Is this a situation you are attempting to duplicate from that terrible film I was forced to watch?"

" _ Hall Pass _ ? No. This is a situation the Midgardians call polyamory. Like, uh... Hogan, Fandral, and Volstagg!"

"You wish the three of us to become bosom brothers in arms?" Loki asked, looking completely confused. The look was adorable on him, which was pretty rude.

"Uh, I meant the other thing."

Loki frowned. "What other thing?"

_Oh, god_ _._ "Are you serious right now? How could you live with a three of them for millennia and _not_ notice? They're banging, dude. All the sex, all the time."

Loki blinked in sudden comprehension. "I had always wondered why they never invited me to their post battle revels, but then, my brother attended them often..."

Darcy waved a hand. "Let's not get off topic. I'm not proposing the three of us become brothers in arms, and I'm not proposing the three of us hold hands and skip down the street, happy-romantic style."

"What are you proposing, exactly?" he asked, regarding her with a serious demeanor. Success! She could now add a third tally mark to her 'got Loki to listen' achievement.

She took a deep breath. "You and I never really... ended things, with everything that happened. So I guess what I'm proposing is we... pick things up where we left off?"

"I was under the impression that was why we had entered this closet. What does any of that have to do with Sergeant Barnes?"

"What it has to do with Bucky is I still want to be with him, too. So yes, I do want to be with you. I totally want you to fuck my brains out in this supply closet."

That was absolutely the wrong thing to say, because it made Loki close the distance between them and seize her around the waist.

"But!" Darcy stopped his lips as they went for hers. "I'm going to be with Bucky, too."

"Right now?" Loki asked, with a puzzled frown.

"Well, obviously not."

"So you will be with me, and then be with Sergeant Barnes."

"Yes, and no?" Darcy rubbed an eyebrow with her hand. "I don't think you're getting this."

"Darcy," Loki said, "The only thing I want to get is my mouth on your beautiful cunt."

"Shit," Darcy replied, getting weak in the knees. Loki held her up. "Okay. Fine. We can talk about this later."

Loki kissed her, and she melted into him.

"Wait," Darcy began, as Loki snaked a hand inside her pants. "You're fucking with me, right?"

"I will be," Loki said, his fingers playing against her skin but not getting any closer to where she wanted them.

"But you get this whole poly thing."

"Of course I do," Loki said, his breath hot against her throat. "What I want is for you to be happy, and if it makes you happy to engage in a relationship with Sergeant Barnes as well as myself, then so be it. As long as I get to have you to myself as often as is possible... within reason, then you should be free to do whatever— _ whomever _ —you wish."

"Awesome, great, glad we got that cleared up. Now  _ touch me _ , for the love of god," Darcy begged. Loki's fingers twitched, and his other hand hovered at her breast, not touching, a tease.

"There is only one deity whose name ought to be on your lips," he whispered, and slipped his fingers between her slick folds.

" _ Loki _ ," Darcy groaned, arching into him.

He kneaded her breast with one hand while the other stroked her slowly. "Yes," he hissed. His fingers moved more quickly, more fervently. "Again."

"Loki, yes! Don't stop..."

"It was you," he confided in her ear as his fingertips circled her clit, "your voice calling out my name, begging me to give you pleasure, that allowed me to stay myself in all I have been through without you."

He alternated between long, slow strokes of her labia and quick, intense attention to her clit, and Darcy clutched his arm, her head thrown back, gasping out exactly what he wanted: pleas for more and praises to Loki.

When her voice started climbing into a higher register, a hot coil of pleasure drawing tighter within her, Loki nipped at her neck and whispered in her ear, "Now come for me, Darcy." So she did, shaking and crying out his name at the rush of endorphins, grabbing onto him and the table so she wouldn't fall over.

"Now," he said, licking his fingers clean of her, "I believe you said something about wanting me to fuck your brains out?"

"Hnngh, gimme a second," she told him, blinking quickly to make sure her eyes were still working.

Loki pressed into her, nudging his hard length against where she was most sensitive, making her gasp. "I ache for you, Darcy," he murmured against her neck.

Darcy spotted this particular supply closet's condom stash just as Loki took her shirt off. He was distracted by her bra and what was beneath it when she tried to reach it and failed. "Condoms," she reported, reaching again.

"Mmhm," he agreed, pushing her pants and panties down off of her hips. She lifted one foot to step out of them, and Loki took the opportunity to lick a stripe from her hole to her clit.

"Loki," she protested with a groan. "I thought—"

He hummed against her and she gasped at the jolt it caused. "My own needs can wait," he decided, then withdrew to lift her up onto the table. It was almost too much when his breath brushed across her pussy and he began to  _ suck _ .

Darcy let out a cry and dug her heel into his back, tangling one of her hands in his hair and pulling, just the way he liked.

Sure enough, he paused to grin up at her. "Do you think you can control  _ me _ , mortal?"

"Oh,  _ fuck _ ," Darcy replied, letting her head fall back onto the table.

"Yes," Loki agreed, and returned to making love to her with his mouth.

She knew there was no way that everyone within earshot could be innocent of what Loki was doing to her in the supply closet. She screamed as he fucked his tongue up into her, touching her in every way she craved, pushing her toward the edge again.

One unexpected outcome of his merciless pleasuring was that Darcy, twitching on the table, stretched out her arm in search of something to grab onto and laid her hand on the box of condoms. She couldn't open it; her fine motor skills had gone along with her language comprehension when Loki had begun to nip at her swollen labia, but protection had been acquired.

" _ Loki _ ," she moaned, when her legs began to shake. "I  _ need _ you."

"I think you do," he agreed, standing and wiping his mouth on his sleeve.

She struggled to sit up while he unbuckled his pants. "Nuh-uh," she said, pushing his hands away. "Shirt off."

"What you need isn't under my shirt," Loki argued. Darcy pointedly took off her bra, watching as Loki's mind changed when it hit the floor. "But it's only fair. Though... there are so many clasps..."

"Well, I don't dress you in the mornings," she said, and took over the pants removal process as he started on his shirt. "Wear a t-shirt next time."

"Asgardian fashion—" he began.

"Shut  _ up _ ," Darcy commanded. "I want you  _ in _ me."

Loki drew in a breath of anticipation and began to work faster. 

Darcy knew that it was easier to get Loki's pants off when he didn't have a raging hard-on, but there were upsides to yanking buckles in that area: Loki hissed every single time her fingers grazed his cock.

"You are doing that on purpose now, mortal," he groaned, when she gave up on the intricate "Asgardian fashion" and palmed him through his pants.

"Fuck yes, I am," Darcy admitted freely, watching with glee as he finally shed his shirt and turned his attention to his pants. Darcy resisted his attempts to dance out of the way of her hands, reaching down lower to tease her fingers lightly along his balls. Loki worked quicker.

"Mortal," he ground out, "you are likely to be my undoing."

"Don't call me that," Darcy said, digging in the condom box as he finally gave up on the buckles and started to shove his pants down anyway. "I wasn't allowed to say any name but yours? Now  _ you _ get to worship  _ me _ ."

She reached out to grasp onto his dick as soon as it was free, and Loki let out an involuntary moan, twitching up into her hand. " _ Darcy _ ."

"That's right," she urged. "Say it again." She tore open a condom with her teeth, pulling him closer by the handle she held, and he let out a breath that was almost a whine, a sound full of need. She squeezed, and commanded, "Say my name, Loki."

"Darcy," he uttered, locking eyes with her as he fought to kick off his pants. "I have never desired you more."

She rolled the condom on with one hand and grasped his hip to position him with the other. "Prove it," she said, and pushed herself off the table to sink down onto him.

Loki let out a broken gasp and Darcy watched as he juggled the different demands on his attention: holding her up, pushing deeper inside her, and the feeling of being joined together again after so long apart.

This was always the best moment for Darcy; the rawest and most vulnerable Loki ever got was when he first slid inside her. She loved to watch his face, the way he tilted his head back, his half-closed eyes, eyebrows drawn, and his mouth, open as though he were about to cry out her name.

"Darcy," he whispered. He held them there for a moment, balls deep and twitching.

And then he began to move.

_ God _ , she'd missed him.

He turned and pushed her against the door, fucking in and out of her like it was his last night on Earth. He nipped at her collarbone and kissed her, and Darcy grabbed a handful of his hair and tugged.

Loki growled and fucked her faster.

"Oh, shit, Loki, yes!" Darcy gasped out. He tilted his hips just so, and suddenly he was  _ perfect _ , slamming into her over and over in the spot she needed it most.

"Darcy," Loki said, a mischievous grin on his face, "I want to feel your beautiful quim fluttering around me. I want to make you scream so the entire  _ city _ knows I have pleased you. Come, Darcy. Come for me again." 

He let go of her hip to brush his thumb roughly over her clit, and Darcy screamed. She wasn't sure the whole city heard, but she wasn't really paying much attention. 

Loki's rhythm stuttered a moment later, and she tilted her hips and yanked on his hair as she watched his eyes roll back in his head when he shuddered and slowly impaled himself on her once, twice, and then one final time.

Darcy tried to catch her breath as Loki set his forehead against hers. "I missed you," he whispered, and then kissed her tenderly.

"Loki," she said, "I absolutely missed you too."

* * *

 

Darcy stood next to Jane on the roof of the Tower with a fake smile plastered over her sadness as they waved goodbye to Loki and Thor. As soon as the brilliant light from the Bifrost had faded and Jane had finished gathering all of the data she was likely to get, she started in with the disapproving glaring. Darcy had expected it, so it was easy to put on an amused smile as she rolled her eyes.

"I can't believe it!" Jane hissed, while Darcy wheeled the heavier things over to the elevator so they could get them back to the lab. "How could you even— What about  _ Bucky _ ?! Remember? Your boyfriend? That you really really like?"

Darcy shook her head and allowed Jane to ramble on.

"Wasn't it just the other day that I saw the two of you sneaking a kiss in the hallway before work? I thought you had planned to spend the entire afternoon Thor and Loki were here in the common room so you wouldn't have to see him! I can't believe you would just throw away an entire relationship that was  _ going places _ just to jump Loki again. He's not worth it, Darce! Not worth the pain you'll go through again when he breaks your heart, and definitely not worth Bucky."

"You're adorable and a half," Darcy told Jane as she pressed the button that would take them to the lab. "What makes you think I don't know all of those things already?"

"Uhh, the fact that you're up here saying goodbye to Loki like you're his girlfriend? The fact that you two spent most of your time in the supply closet and in your bedroom while they were here? I love you, Darcy, and I don't want to see you hurt. And I don't want to see Bucky hurt, either! Don't hurt him, Darce. He's ten times a better man than Loki is."

Darcy shrugged. "What's done is done," she said, bobbing her eyebrows. "And it was done well."

"Okay, ew," Jane said, holding out her hand to halt Darcy's oversharing tendencies. "But what you did to Bucky wasn't cool, Darcy. The two of you were just so cute together, and you want to throw it all away? For Asgard's Most Wanted?"

Darcy winked at her. "Who said I was throwing anything away?"

Jane stared at her, mouth agape, as she pushed one of the bigger machines out of the elevator and back to its spot in the lab. She was still standing gobsmacked when Darcy returned, so she said, "Things aren't always what they seem at first glance, Janey."

* * *

 

"You _sure_ you're okay, Jerk?" Steve was asking as Darcy neared the common area. "Stark goes on about his soundproofing, but even _he_ heard them last—"

"I'm  _ fine _ , Stevie," Bucky interrupted. "I told you, it's just like Dum Dum used to brag about."

"How many girls he nailed in that village?" Steve began, sounding baffled.

Bucky laughed and winked at Darcy when he spotted her. "Nah, I mean when he used to brag about his girl back home, how the second best thing about her was that she slapped him on the ass before he shipped out and told him to have a good time, and the best thing about her—"

"—Was her cans," Steve finished, and turned around just as Darcy was fitting herself against Bucky like she'd never been gone. "Oh, Darcy, I didn't realize you were—"

"It's okay, Cap," Darcy assured him. "I've heard worse, believe me."

"Have a good weekend?" Bucky asked, kissing her temple.

"Sounds like you know I did," Darcy replied, kissing him back.

Steve was blushing and looking uncomfortable. Darcy was about to reassure him, but Bucky beat her to it.

"Don't give me that 'innocent Captain America' look, you punk. This is just like the shenanigans that you, Peggy, and Howard used to get up to, so you can stuff your judgments."

Seeing Steve gaping the exact way she'd left Jane was too comical not to laugh at, so Darcy did.

"Did everyone know?" Steve squeaked eventually. 

"Just me and Tim," Bucky told him.

"But this weekend... you... were with me the whole time they were—"

"Okay, maybe not  _ just _ like what you three had going on," Bucky interrupted with a grin, "but close enough to understand that my girl and I—and whoever else we decide to bring into the equation—don't need your sass."

Steve gulped and nodded. "Sorry, Darcy." 

"It's not a problem, Steve," she assured him. "Though, if you have a minute, could you maybe stop by the lab and explain to Jane what happens when a man and a woman and a man and woman love each other very much?"

**Author's Note:**

> Leave me nice comments! A rec to your favorite Tasertricks, Wintershock, etc would be great! Or emojis, I always like those. :D
> 
> [Reblog on tumblr](http://catrinasl.tumblr.com/post/169231630068/equation)
> 
> Tumblr: [catrinasl](http://catrinasl.tumblr.com)
> 
> Twitter: [@Catrina_SL](http://twitter.com/Catrina_SL)

**Works inspired by this one:**

  * [Safehouse Rendezvous](https://archiveofourown.org/works/13562256) by [CatrinaSL](https://archiveofourown.org/users/CatrinaSL/pseuds/CatrinaSL)




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